Zenith XBV613 Service Manual - Page 18

Servo Circuit

Get Zenith XBV613 - DVD/VCR Combination PDF manuals and user guides
UPC - 719192169715
View all Zenith XBV613 manuals
Add to My Manuals
Save this manual to your list of manuals

Page 18 highlights

3. SERVO CIRCUIT (1) Unstable Video in PB MODE Unstable Video in PB Mode. YES Does the Noise level of the screen change periodically? YES Do the CTL pulses appear NO at IC501 Pin97? YES Does the CFG waveform appear at IC501 Pin87? YES On tracking do the CTL NO pulses move? YES Does the Video Envelope NO waveform appear at IC501 Pin9? YES Replace IC501. (2) When the Drum Motor (2) doesn't run. When the Drum Motor doesn't run, Does 12V appear at PMC01 Pin8? NO YES Does 2.8V appear at PMC01 Pin12? NO YES Check the connector (PMC01) and the Drum Motor Ass'y. Is adjusting the height of the CTL Head accurate? NO Readjust the height of the CTL Head. Replace IC501. Refer to "When the Y signal doesn't appear on the screen in PB Mode". Refer to "(2) No 12VA of Power section" Do the Drum PWM Pulses appear at the IC501 Pin76? YES Are the foil patterns and the Components between IC501 Pin76 and PMC01 Pin12 shorted? NO YES Do the DFG Pulses appear at PMC01 Pin11? NO Replace the DRUM-M or CAP-M. Do the DFG Pulses appear at IC501 Pin90? NO YES Do the Drum PWM Pulses NO appear at IC501 Pin76? Are the foil patterns and the Components between IC501 Pin 90 and PMC01 Pin11 shorted? Replace IC501. YES Are the connecting patterns and the Components between IC501 Pin76 and PMC01 Pin12 shorted? 3-7

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
  • 99
  • 100
  • 101
  • 102
  • 103
  • 104
  • 105
  • 106
  • 107
  • 108
  • 109
  • 110
  • 111
  • 112
  • 113
  • 114
  • 115
  • 116
  • 117
  • 118
  • 119
  • 120
  • 121
  • 122
  • 123
  • 124
  • 125
  • 126
  • 127
  • 128
3-7
3. SERVO CIRCUIT
(1) Unstable Video in PB MODE
Unstable Video in
PB Mode.
Does the Noise level of the
screen change
periodically?
Do the CTL pulses appear
at IC501 Pin97?
Is adjusting the height of
the CTL Head accurate?
Readjust the height of the
CTL Head.
Replace IC501.
Refer to
“
When the Y signal
doesn
’
t appear on the
screen in PB Mode
”
.
Does the CFG waveform
appear at IC501 Pin87?
On tracking do the CTL
pulses move?
Does the Video Envelope
waveform appear at IC501
Pin9?
Replace IC501.
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
(2) When the Drum Motor
(2)
doesn
’
t run.
Do the DFG Pulses appear
at PMC01 Pin11?
Replace the DRUM-M or
CAP-M.
Are the foil patterns and
the Components between
IC501 Pin 90 and PMC01
Pin11 shorted?
Replace IC501.
Refer to
“
(2)
No 12VA of Power section
”
Do the Drum PWM Pulses
appear at the IC501
Pin76?
Are the foil patterns and
the Components between
IC501 Pin76 and PMC01
Pin12 shorted?
Do the DFG Pulses appear
at IC501 Pin90?
Do the Drum PWM Pulses
appear at IC501 Pin76?
Are the connecting patterns and the Components
between IC501 Pin76 and PMC01 Pin12 shorted?
When the Drum Motor
doesn
’
t run,
Does 12V appear at
PMC01 Pin8?
Does 2.8V appear at
PMC01 Pin12?
Check the connector
(PMC01) and the Drum
Motor Ass
’
y.
NO
YES
YES
YES
NO
NO
NO
NO
NO
YES
YES
YES